Plank gib for power plate printing presses



PLANK GIB FOR POWER PLATE PRINTING PRESSES Filed Nov. 1'7, 1938 2 Sheets-Sheet l IN VENT OR.

ATTORNEYS.

July 4, 1939. A. A. GROSSARTH PLANK GIB FOR POWER PLATE PRINTING PRESSES Filed Nov. 1'7, 1958 2 Sheets-Sheet 2 INVENT OR. BY QZerZ CZ-Groazsari/a 50mm, W

ATToRNEY Patented July 4, 1939 PATENT OFFICE PLANK GIB FOR POWER PLATE PRINTING PRESSES Albert A. Grossarth, La Grange, Ill., assignor to Miehle Printing Press & Manufacturing Company, Chicago, 111., a corporation of Illinois Application November 1'7, 1938, Serial No. 240,933

'7 Claims.

This invention pertains to printing presses and it more especially concerns that class of presses on which the printing is accomplished from flat, engraved plates which are mounted on a plank 5 so arranged that after a plate has been inked in,

the plank, together with the inked plate, is advanced to a wiper mechanism where the surplus ink is removed from the surface of the plate prior to pulling the impression.

The planks of such presses are usually supported on guide ways provided on the frame of the press and are advanced from station to station by means of an endless chain drive, or by any other suitable mechanism. D

Wiper mechanisms used in presses of this type include a pad over which is stretched an absorbent material, preferably unwound from a roll and fed at intervals over said pad to present a fresh length of material to the plate to be wiped. Dur- 20 ing the wiping operation the pad is lowered onto the surface of the printing plate and moved over it under some pressure in any desired path so that the surplus ink will be removed from said surface.

It has been found that due to the clearance that must be provided between the sides of the planks and the walls of the guide ways in order to assure free movement of the planks between said Ways, considerable side slap of the planks 3 occurs as they pass beneath the wiper pad during the wiping operation, producing an objectionable noise.

With a view to overcoming such noise and assuring a smooth advance of the planks while they 33 are being wiped, I propose to provide simple and effective means whereby such side slap will be entirely eliminated.

Other detail features of one preferred form of mechanism constituting my invention will become apparent from the following description and appended claims read in the light of the accompanying drawings of which:

Figure 1 is a plan view showing in part the arrangement of a wiping mechanism of well-known 50 fluence of the parts which constitute my invention.

The wiper parts, such as the offand on-winding rollers, pad holder, crank disk and other associated parts whereby motion is imparted to the 55 wiper pad, are mounted on upright frame members or brackets l and II which are arranged at each side of the press.

These brackets are preferably connected by a hood I2 which extends over the wiper pad. The on-winding roller l3, as well as the off-winding roller, not shown, are mounted for convenient removal so that they may be readily replaced. The stroke or sweepf is imparted to the wiper pad by means of a crank disk 14 driven in any suitable manner. Preferably I also provide means where- .by tension can be applied to the web of wiping material and means whereby the stroke of feed of said web may be varied.

All of the above referred to devices and means are more or less of a conventional type and are r not described in detail here because they form no part of the present invention but are mentioned merely for a better understanding of the function of the device in which my invention is embodied.

Having now more specific reference to Figure 2 of the drawings, it will be seen that the bracket [0 is machined out to form a recess I5 which will accommodate a wedge member l6. Both of the side faces of the latter are machined, the face ll bearing against the machined face of the recess l5, while the other face [8 normally projects slightly into the path of the plank which travels within the guide ways 2|, 22 in the direction indicated by the arrow.

The wedge I6 is supported by means of guide pins 23 and 24, preferably secured Within the ends of said wedge and arranged to slide in bores provided in brackets 25 and 26 respectively. By

means of an expansion coil spring 21 the wedge IE is urged in the direction indicated by the arrow. The extent of this movement of the wedge, indicated in broken lines, is determined by the collar 28 abutting against the bracket 26. Normally therefore, the machined face l8 of the wedge projects slightly into the space between the uprights l0 and II. Consequently, when the plank Zll reaches the position as shown in Figure 2, its corner 29 will engage the upper edge 30 of the wedge, which edge, as will be seen, is slightly tapered. During the continued advance of the plank 20, the wedge I6 is being forced outwardly and downwardly against the pressure of the spring 21, its face I! sliding in contact with the face l5 of the bracket H]. In turn the face 3| of the plank will be forced tightly against the machined face 32 of the bracket ll, thereby metal to metal contact is maintained between the walls of the brackets N, H and the sides of the plank 20. The force of the spring 21 is so calculated that it will fully overcome any lateral tendency of movement of the plank 20 caused due to the pressure exerted by the wiper pad while in contact with the printing plate during the wiping operation, thereby entirely eliminating side slap of the plank.

The same result could of course be accomplished by means other than a spring pressed wedge as described, therefore I desire to cover any such devices that will come within the meaning of the appended claims.

I claim:

1. In a power plate printing press, the combination of a printing plate carrying plank, guide ways for said plank, and means acting on said plank to eliminate side slap of the plank during its travel between said guide ways and while the plate is being wiped.

2. In a power plate printing press, the combination of a printing plate carrying plank, guide ways for said plank, and a spring actuated wedge member acting on said plank to eliminate side slap of the plank during its travel between said guide ways and while the plate is being wiped.

3. In a power plate printing press, the combination of a printing plate carrying plank, guide ways for said plank, and a spring actuated Wedge member normally extending into the path of said plank and arranged to be depressed thereby during its travel between said guide ways and while the plate is being wiped, thereby eliminating side slap of the plank during wiping.

4. In a power plate printing press, the combination of a printing plate carrying plank, guide ways for said plank, and a spring actuated wedge member normally extending into the path of said plank and arranged to be depressed thereby during its travel between said guide ways, one end of that side of said wedge which bears against the plank being tapered.

5. In a power plate printing press, the combination of brackets provided on the main frame of the press and adapted to support wiping mechanism, guide ways for a printing plate carrying plank and extending between said brackets, and means arranged within one of said brackets to act on said plank in order to elminate side slap while the plate on said plank is being wiped.

6. In a power plate printing press, the combination of brackets provided on the main frame of the press and adapted to support wiping mechanism, guide ways for a printing plate carrying plank and extending between said brackets, a wedge member slidably supported within one of said brackets, and pressure means acting on said wedge member to move it into the path and hold it against one side of said plank in order to eliminate side slap while the plate on said plank is being wiped.

7. In a power plate printing press, the combination of brackets provided on the main frame of the press and adapted to support wiping mechanism, guide ways for a printing plate carrying plank and extending between said brackets, a wedge member supported at each end and slidably mounted within one of said brackets, and pressure means acting on said wedge member to move it into the path and hold it against one side of said plank in order to eliminate side slap while the plate on said plank is being wiped.

ALBERT A. GROSSARTH. 

